Properties of bio-based gum Arabic/clay aerogels

⿢⿿Green⿿ gum Arabic/clay aerogels were prepared using a freeze-drying process.⿢The unique solvent used in the preparation process was water.⿢Gum Arabic aerogels exhibit a lamellar structure created by the ice template.⿢The thermal stability and flame retardancy were improved by clay addition.

Lightweight bio-based aerogels from sustainable gum Arabic (GA) and sodium montmorillonite (Na+-MMT) clay were prepared by means of a simple freeze-drying process. GA/clay aerogels showed high porosity (87.9%⿿94.9%) of mainly open type and the mechanical properties were improved by the clay. When 40% of clay was added to pure GA, the specific modulus and the absorbed energy of resultant aerogels increased by 1.6 and 4.2 times respectively. On the other hand, the exponent value for modulus in the power-law model for cellular materials increased from 1.95 to 3.28 due to the more anisotropic structures induced by the presence of the clay. In terms of thermal stability and flame retardancy, clay content played a dominant role. With 50% of clay loading, the initial decomposition temperature increased by nearly 16 °C and the peak of heat release rate was 3-fold reduced.

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